A method and system for receiving energy selective image data relating to an examination object using a counting, digital X-ray detector, together with a counting, digital X-ray detector and an X-ray system are provided. The X-ray detector includes an X-ray converter for direct or indirect conversion of X-rays into an electrical signal, and a matrix including a plurality of counting pixel elements. For each pixel element of the plurality of counting pixel elements, at least one modifiable threshold value, above which an incoming signal is counted using a memory unit, is applicable.

An improved dual energy CT imaging system for providing improved imaging and improved material identification.

Structures and methods operable to detect radiation are described. The structure includes a dual-layer detector imaging device that permits one-shot of x-rays for dual-energy imaging. In one embodiment, a front layer of the detector includes a photon counting detector and aback layer of the detector includes an an x-ray radiation source for absorbing x-ray radiation to separate radiation into low energy and high energy components for incidence upon an imaging object. In an embodiment, the imaging object includes a contrast agent material having a characteristic K-edge atomic energy band level, and the separation filter absorbing the X-ray radiation is near the K-edge atomic energy band level.

According to an embodiment, a photon counting CT apparatus includes a scintillator, a photodiode array, a holder, a divider, and an image generator. The scintillator is configured to convert X-rays into light. The array includes first and second pixels. The first pixel includes a photodiode in a first range receiving the light emitted from the scintillator. The photodiode outputs an electrical signal based on the light. The second pixel includes a photodiode in a second range different from the first range. The holder is circuitry configured to hold a value of an electrical signal output by the second pixel. The divider circuitry is configured to count the number of photons of light incident on the first pixel by dividing an integrated value of electrical signals output by the first pixel by the held value. The image generator is circuitry configured to reconstruct an image based on the counted number.

An apparatus for performing nanoparticle-assisted external beam radiotherapy includes an X-ray spectrometer having an optical axis, an X-ray filter, and a mobile holding structure suitable for holding the X-ray filter and the X-ray spectrometer in a first and a second relative position, and for switching from the first to the second relative position while simultaneously allowing the positioning of a patient body part in a target region including a target point; wherein: the first and second relative positions of the X-ray filter and the X-ray spectrometer are such that an X-ray beam emitted from the X-ray source crosses the X-ray filter before reaching the target point, a propagation direction of the X-ray beam forming an angle different from 0 and 180 with the optical axis of the X-ray spectrometer; and the second relative position is obtained by inverting the relative positions of the X-ray filter and of the X-ray spectrometer with respect to the patient body part. A method of determining an X-ray dose delivered at a region of a patient body using the apparatus is provided.

A method is for controlling an x-ray imaging device, in particular a computed tomography device. The x-ray imaging device includes an x-ray source and a photon counting detector as an x-ray detector. The methods includes, for an image acquisition process of a patient: determining at least one input parameter relating to at least one of an attenuation property of the patient and a purpose of the image acquisition; at least one of determining or adapting at least one operation parameter of the x-ray detector, dependent upon the at least one input parameter determined; and performing the image acquisition using the at least one operation parameter determined or adapted.

Aspects of the invention are directed to systems and methods for generating spectral computed tomography data for spectral X-ray image reconstruction using of pixelated k-edge apertures. A method is provided for generating a spectral computed tomography. The method includes the steps of generating a plurality of X-ray beams; encoding the plurality of X-ray beams by transmitting the plurality of beams through a pixelated K-edge coded aperture structure; detecting the encoded plurality of X-ray beams; and reconstructing a spectral CT image from the encoded plurality of X-ray beams.

An image acquisition unit acquires two radiographic images based on radiation which has different energy distributions and has been transmitted through a subject including a soft part and a bone part. A subtraction unit performs weighting subtraction using a predetermined initial weighting coefficient between corresponding pixels of the two radiographic images to derive a soft part image obtained by extracting the soft part of the subject and a bone part image obtained by extracting the bone part of the subject. A weighting coefficient derivation unit derives a new weighting coefficient on the basis of a pixel value of the bone part included in the bone part image. The subtraction unit performs the weighting subtraction on the two radiographic images using the new weighting coefficient to derive a new soft part image and a new bone part image.

Systems and method for performing X-ray computed tomography (CT) that can improve spectral separation and decrease motion artifacts without increasing radiation dose are provided. The systems and method can be used with either a kVp-switching source or a single-kVp source. When used with a kVp-switching source, an absorption grating and a filter grating can be disposed between the X-ray source and the sample to be imaged. Relative motion of the filter and absorption gratings can by synchronized to the kVp switching frequency of the X-ray source. When used with a single-kVp source, a combination of absorption and filter gratings can be used and can be driven in an oscillation movement that is optimized for a single-kVp X-ray source. With a single-kVp source, the absorption grating can also be omitted and the filter grating can remain stationary.

An X-ray computed tomography apparatus according to an embodiment stores a plurality of reference count data indicative of energy spectra of X-rays, which are associated with a plurality of tube voltages or tube currents. Estimation circuitry estimates a tube voltage or a tube current at a time of X-ray irradiation, based on a comparison of energy spectra between second count data and each of the plurality of reference count data. Correction circuitry corrects first count data acquired together with the second count data, by using an energy spectrum calculated based on the estimated tube voltage or tube current. Reconstruction circuitry reconstructs medical image data, based on the corrected first count data.